Within each essential protein complex, essential proteins tend to have a higher average intracomplex degree.

Num Complexes Tested gives the number of complexes considered in each of the three networks; each such complex was required to have at least two essential proteins and at least two non-essential proteins, each with intracomplex interactions. Num Complexes with Higher Avg Essential Degree gives the number of complexes among the tested complexes where the essential proteins have higher intracomplex degree on average than the non-essential proteins. To determine whether this number is significant, we randomly permuted essentiality assignments and computed the number of complexes with higher average intracomplex degrees for essential proteins. Empirical -value gives the fraction of random permutations where the number of such complexes is greater than or equal to the actual number, computed over 10,000 permutations.